1 / 8One in four of the world's population will suffer from hearing problems by 2050, the World Health Organization warned Tuesday, calling for extra investment in prevention and treatment.2 / 8The first-ever global report on hearing said that the causes of many of the problems -- such as infections, diseases, birth defects, noise exposure and lifestyle choices -- could be prevented.3 / 8The report proposed a package of measures, which it calculated would cost $1.33 per person per year.4 / 8Against that, it set the figure of nearly a trillion US dollars lost every year because the issue was not being properly addressed.5 / 8'Failure to act will be costly in terms of the health and well-being of those affected, and the financial losses arising from their exclusion from communication, education and employment,' said the report.6 / 8One in five people worldwide have hearing problems currently, it said.7 / 8But the report warned: 'The number of people with hearing loss may increase more than 1.5-fold during the next three decades' to 2.5 billion people -- up from 1.6 billion in 2019.8 / 8Of the 2.5 billion, 700 million would in 2050 have a serious enough condition to require some kind of treatment, it added -- up from 430 million in 2019. Much of the expected rise is due to demographic and population trends, it added. A major contributor to hearing problems is a lack of access to care, which is particularly striking in low-income countries where there are far fewer professionals available to treat them.